[New trematode genera from fishes of the southern Atlantic].

Two new genera of the lepocreadiid trematodes, Gibsonia gen. n., (type species--G. hastata sp. n.) from Macrourus carinatus Günther, 1878 (Macrouridae), collected in the Falkland Islands area, and Muraenolepitrema gen. n. (type species--M. magnatestis sp. n.) from Muraenolepis microps Lönnberg, 1905 (Muraenolepidae), collected in the South Georgia Island area, are described. Gibsonia gen. n. differs from all known genera of the family Lepocreadiidae by unusual body shape divided into 2 parts, suctorial formations, great number of glandular cells and a muscular bulge of the body sides; it differs from the closely related genus Lepidapedon by separate genital pores. Muraenolepitrema gen. n. differs from Myzoxenus by bursa shape, separate genital pores, lobed shape of genital organs.